During the past two decades, the relationship between neuronal monoamines in the brain and a variety of diseases and conditions has been appreciated and investigated. The discovery of selective monoamine reuptake inhibitors has provided the medical community with exciting new tools with the potential for treatment of several physiological and psychological disorders. Reuptake inhibitors increase the levels of endogenous monoamines by inhibiting the neuronal mechanism for recovering the monoamine from the synapse without interfering with the neuronal receptors. If the reuptake inhibitor is selective for a particular monoamine, undesirable side-effects from the therapy can be reduced.
Fluoxetine, a selective inhibitor of serotonin reuptake, has gained wide acceptance as a therapy for the treatment of depression and eating disorders, and is under active investigation for the treatment of other disorders. Similarly, tomoxetine hydrochloride [(-)-N-methyl-3-(2-methylphenoxy)propanamine hydrochloride] is a selective inhibitor of norepinephrine uptake being investigated clinically for the treatment of urinary incontinence. These compounds are among many taught in U.S. Pat. Nos. 4,018,895, 4,194,009, 4,314,081 and 5,026,707 as being potent inhibitors of the uptake of various physiologically active monoamines, including serotonin, norepinephrine and dopamine.
Certain piperidinylindoles and tetrahydropyridinylindoles are known to be agonists at the serotonin 5-HT.sub.1 -like receptor (Baker et al., U.S. Pat. No. 5,298,520), and to have affinity for the serotonin 5-HT.sub.1, 5-HT.sub.1A, and 5-HT.sub.2 receptors (Taylor et al., Molecular Pharmacology, 34, 42-53 (1988)). Certain piperidinylbenzothiophenes are known to be serotonin 5-HT.sub.2 antagonists (Watanabe et al., Journal of Heterocyclic Chemistry, 30, 445 (1993)). The ability of these classes of compounds to inhibit the reuptake of serotonin, however, has heretofore not been appreciated.